general improvements in the error reporting

chain-impl-mockchain/src/account.rs

@@ -27,3 +27,9 @@ pub type Secret = key::AccountSecretKey;
 
 /// The public ledger of all accounts associated with their current state
 pub type Ledger = account::Ledger<Identifier>;
+
+impl std::fmt::Display for Identifier {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}

chain-impl-mockchain/src/accounting/account.rs

@@ -7,38 +7,16 @@
 use crate::value::*;
 use imhamt::{Hamt, InsertError, UpdateError};
 use std::collections::hash_map::DefaultHasher;
-use std::fmt::{self, Display, Formatter};
 use std::hash::Hash;
 
-/// Possible errors during an account operation
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub enum LedgerError {
-    NonExistent,
-    AlreadyExists,
-    NeedTotalWithdrawal,
-    NonZero,
-    ValueError(ValueError),
-}
-
-impl Display for LedgerError {
-    fn fmt(&self, formatter: &mut Formatter) -> Result<(), fmt::Error> {
-        match self {
-            LedgerError::NonExistent => "Account does not exist",
-            LedgerError::AlreadyExists => "Account already exists",
-            LedgerError::NeedTotalWithdrawal => {
-                "Operation counter reached its maximum and next operation must be full withdrawal"
-            }
-            LedgerError::NonZero => "Removed account is not empty",
-            LedgerError::ValueError(_) => "Value calculation failed",
-        }
-        .fmt(formatter)
-    }
-}
-
-impl From<ValueError> for LedgerError {
-    fn from(e: ValueError) -> Self {
-        LedgerError::ValueError(e)
-    }
+custom_error! {
+    #[derive(Clone, PartialEq, Eq)]
+    pub LedgerError
+        NonExistent = "Account does not exist",
+        AlreadyExists = "Account already exists",
+        NeedTotalWithdrawal = "Operation counter reached its maximum and next operation must be full withdrawal",
+        NonZero = "Removed account is not empty",
+        ValueError{ source: ValueError } = "Value calculation failed",
 }
 
 impl From<UpdateError<LedgerError>> for LedgerError {

chain-impl-mockchain/src/leadership/genesis/mod.rs

@@ -31,6 +31,11 @@ pub struct GenesisLeaderSelection {
     active_slots_coeff: ActiveSlotsCoeff,
 }
 
+custom_error! {GenesisError
+    InvalidEpoch { expected: Epoch, actual: Epoch } = "Wrong epoch, expected epoch {expected} but received block at epoch {actual}",
+    TotalStakeIsZero = "Total stake is null",
+}
+
 impl GenesisLeaderSelection {
     pub fn new(epoch: Epoch, ledger: &Ledger) -> Self {
         GenesisLeaderSelection {
@@ -49,8 +54,13 @@ impl GenesisLeaderSelection {
         date: BlockDate,
     ) -> Result<Option<Witness>, Error> {
         if date.epoch != self.epoch {
-            // TODO: add more error details: invalid Date
-            return Err(Error::new(ErrorKind::Failure));
+            return Err(Error::new_(
+                ErrorKind::Failure,
+                GenesisError::InvalidEpoch {
+                    actual: date.epoch,
+                    expected: self.epoch,
+                },
+            ));
         }
 
         let stake_snapshot = &self.distribution;
@@ -62,8 +72,10 @@ impl GenesisLeaderSelection {
                 let total_stake: Value = stake_snapshot.total_stake();
 
                 if total_stake == Value::zero() {
-                    // TODO: give more info about the error here...
-                    return Err(Error::new(ErrorKind::Failure));
+                    return Err(Error::new_(
+                        ErrorKind::Failure,
+                        GenesisError::TotalStakeIsZero,
+                    ));
                 }
 
                 let percent_stake = PercentStake {
@@ -83,8 +95,13 @@ impl GenesisLeaderSelection {
 
     pub(crate) fn verify(&self, block_header: &Header) -> Verification {
         if block_header.block_date().epoch != self.epoch {
-            // TODO: add more error details: invalid Date
-            return Verification::Failure(Error::new(ErrorKind::Failure));
+            return Verification::Failure(Error::new_(
+                ErrorKind::Failure,
+                GenesisError::InvalidEpoch {
+                    expected: self.epoch,
+                    actual: block_header.block_date().epoch,
+                },
+            ));
         }
 
         let stake_snapshot = &self.distribution;

chain-impl-mockchain/src/leadership/mod.rs

@@ -93,6 +93,9 @@ impl LeadershipConsensus {
             LeadershipConsensus::Bft(_) if block_version == BlockVersion::Ed25519Signed => {
                 Verification::Success
             }
+            LeadershipConsensus::GenesisPraos(_) if block_version == BlockVersion::KesVrfproof => {
+                Verification::Success
+            }
             _ => Verification::Failure(Error::new(ErrorKind::IncompatibleBlockVersion)),
         }
     }
@@ -232,10 +235,13 @@ impl Error {
         }
     }
 
-    pub fn new_(kind: ErrorKind, cause: Box<dyn std::error::Error>) -> Self {
+    pub fn new_<E>(kind: ErrorKind, cause: E) -> Self
+    where
+        E: std::error::Error + 'static,
+    {
         Error {
             kind: kind,
-            cause: Some(cause),
+            cause: Some(Box::new(cause)),
         }
     }
 }